Transformer.



PATENTED MAY 30, 1905.

C. L'E G. FORTESGUE.

v TRANSPORMER.

Win11' INVENTOR ms. afm

a; AT'TORNEY WITNESSES: v

PATENTED MAY 30, 1905.

C. LE G. FORTBSCUE.

TRANSFORMBR.

APPLICATION FILED 51:21:30. 1903.

2 SHEETS-SHEET 2.

NVENTU? ATTORNEY W/TNESSES:

UNITED STATES Patented May{30, 190 5.

PATENT OFFICE.,

TO W ESTINGHOUSE ELECTRIC PORATION OF PENNSYLVANIA.

& MANUFACTURING- COMPANY, A COR- TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 791,021, dated May 30,1905.

Application filed September 30, 1903. Serial No. 175,223.

T0 all 7011/0721/ it 1li/(ty erf/tecra:

Be it known that l, CHARLEs LE (5r. Foe- TESCUE, a subject of the Kingof Great Britain, and a resident of lilkinsburg in the county ofAllegheny and State of Pennsylvania, have invented a new and useful'improvement in Transformers, of which the following is a specification.

My invention relates to transformers employed in connection withalternating-current systems of distribution; and it has for its objectto provide transformer core plates or punchings of such form as toinsure a maximum economy of material and such as may be easily andexpeditiously assembled without danger of injury to the coil insulation.

ln the accompanying drawings, Figure 1 is a view in transverse sectionof a transformer constructed in accordance with my invention.

Fig. 2 is a perspective view of a transformercore, some of the platesheilig' omitted. Fig. 3 is a view of a strip or blank of sheet-irondivided in accordance with my invention.

In the manufacture of transformers it is eX- tremely desirable toprovide core-plates of such form as to utilize a maximum percentage ofthe stoel; from which the plates are punched and also such as to providea core havinglow reluctance to the magnetic flux. The coreplatesheretofore generally used in the manufacture of transformers of theshell type possess the disadvantage of being difficult to assemble andrequiring a large amount of labor in the operation; but one of the mostserious objections to the use of the form of punchings most commonlyemployed is the cutting and tearing of the insulation d u ringtheassembling operation. These objections and others I avoid in a manner tobehereinafter more fully described.

The main portion of the iron core consists of plates 1 of substantiallyE shape, the middle cross-bar 2 being' of substantially double the widthof the end cross-bars 3 and 4; and having a stepped portion 5, due tothe removal of a square portion 6, the side of the square being equal tothe width of the end cross-bars. The end cross-bar 4 is shorter than thebar 3 by an amount equal to its width.

rlhe side bars T are of sullicient length to span the uninclosed sidesof the openings 8 and 9 and the width of an end cross-bar. The doublerectangles forming the core are completed by placing the bars T at rightangles to the cross-bars, so that their inner ends lit into the steppedportions of the middle cross-bar 2 and their outer ends into the spacesbetween the ends of the bars 3. The corners of the rectangles may be cutaway, as shown at 10, 11, 12, 13, 14, and 15, in order to decrease theweight of the core, or the plates may be left with sharp corners, ifpreferred.

A plurality of the E-platcs are preferably placed together to form agroup in order to facilitate the assembling, and alternate groups arereversed with respect to each other, substantially as shown in Fig. Q,in order to reduce the reluctance of the core. The requisite number ofthe groups of E-plates to form the core are built up, and the coils 16,17, 18, and 19 are then placed in position around the central part 2 andwithin the spaces 8 and 9.

Non-conducting material 2O of suitable form and dimensions is placed inthe rectangles before the coils are assembled, and the projectingportions are subsequently carefully wrapped about the coils. '.l he sidebars 7 are then placed in position substantially as indicated in Figs. 1and 2. Herein lies a great advantage of my improvement over theconstruction commonly employed in that the major portion of the core maybe assembled separately from the coils. Heretofore the coils were firstassembled and then wrapped with non-conducting material and boundtogether by means of tape or cord, after which the entire core was builtup around the coils. It is unnecessary to bind together the coils of atransformer constructed in accordance with my invention, and itisdesirable not to do so, since the coils may then be more easily removedfor repairs.

In Fig. 3 l have shown how the E-plates may be punched from strips ofsheet metal so as to afford a maximum economy of material, the shadedportions indicating the waste material. The sheet-metal blanks 2l areWider than the E-plates by an amount equal to the width of the endcross-bars 3 and 4. The

plates 7 may be punched from new sheetmetal'blanks with'little or nowaste, or they .maybe punched from Waste material result- .formersoconstructed has a..low degree oi' reluctance to the magnetic'fiux.

The .forms of Vthe several lparts and their Vrelative proportions may besomewhat varied within thescope of my invention, andI therefforedisclaim any intention to restrict the'inventicn to :any narrower-limitsthan may be imposed-by-fthe prior art and the demands of satisfactoryservice.

I- claim asmy invention- 1. A laminated transformer-core consisting ofsuccessive E-shaped elements the middle cross-bars of which have stepped.free ends land the-end cross-bars of which are of substantiallyone-half 'thewidthof the middle cross-bars and of unequal length, andseparate plates at right angles tothe crossbars and A completingtherectangular inclosures forthe Winding. v

2. Alaminated transformer-core consisting of successivelE-shapedelements, some of which are transposed with respect tothe others, themiddle cross-bars of `which have-stepped free ends and the endcross-bars of which are of substantially 'one-half the width ofthemiddlecross-barsand of unequallength, and separate plates .at rightangles to the crossbars and completing the rectangular linclosures forthe winding.

3. A laminated transformer-core consisting of successive groups of`Eshaped elements alternately transposed with respect to each other themiddle cross-bars of which have stepped free ends and the end cross-barsof which are of substantially one-half the width l of the middlecross-bars and of unequal length,

and separate plates at right angles tothe crossbarsand completing therectangular inclosures for the winding.

4. A laminated transformer-core comprising a-plurality ofalternately-reversed sets of E-shaped plates the middle cross-bars ofwhich have stepped free ends and the end crossbars of which are ofsubstantiallyone-half the width ofthe middle bar` and independent setsof bars the ends oi which are seated in the steps in the middle bars:and in the spaces between the longer. end bars.

5. A transformercore-plate ofE shape,fthe end bars of'which aresubstantially one-half the width of the middle bar and of unequal lengthand :the -middle bar of which has a stepped free end forming two lengths.the shorter of which is adjacent to the longer end bar.

6. An.electrical-transformer comprising a plurality of grou psofalternately-reversed E- shaped plates having middle-bars provided withstepped free ends and end bars of substantially one-half the width'ofthe middle bars and of` unequal length, coils surrounding themiddlebarsand groups of straightbarsthe endsfof which lit into thestepsin the ends of the middle bars and :between thev ends of thelonge-r end bars.

.7. An electrical transformer comprising coils anda core surrounding'thesame, said core comprisinga set of supe1posed,fE-shaped plates and `twosets of :removableplates for closingthe spaces between the end` and'middie bars of the E-s'haped structure.

- Intestimony `whereofl have hereunto subscribed my namethis 28th day ofSeptember, 1903.

-CHARLES LE -G. FORTESOUE. 'VVitnessess I. L. GRIFFITH, :BIRNEY HINEs

